UNIVERSITY   OF   CALIFORNIA       AGRICULTURAL    EXPERIMENT   STATION 

BENJ.    IDE    WHEELER,    PRESIDENT 


COLLEGE   OF  AGRICULTURE 
BERKELEY 


THOMAS    FORSYTH     HUNT,    DEAN    AND    DIRECTOR 

H.    E.     VAN     NORMAN,    Vice-Dir  ector    and    Dean 

University    Farm    School 


CIRCULAR  No.  147 
(February,  1916) 

TOMATO  GROWING  IN  CALIFORNIA 

By  STANLEY  S.  ROGERS 


CONTENTS 

PAGE 

Importance  in  California 1 

Yield  2 

Cost  of  Production  and  Prices  Received  2 

Culture  Requirements  2 

Soil   2 

Climate  3 

Moisture  3 

Preparation  of  the  Soil  3 

Growing  the  Plants  in  the  Seed  Beds  4 

Planting  in  the  Field  5 

Cultivation    6 

Irrigation   6 

Harvesting 7 

Varieties  S 

Diseases   9 


IMPORTANCE  IN  CALIFORNIA 

Owing  to  the  favorable  soil,  moisture  and  climatic  conditions  for 
growing  tomatoes  in  many  sections  of  California,  the  culture  of  this 
crop  for  the  canneries,  fresh  markets  and  eastern  shipments  has  long 
been  an  important  industry.  During  the  season  of  1914,  there  were 
approximately  200  carloads  of  tomatoes  raised  in  this  state  for  can- 
ning, of  which  150  carloads  came  from  the  southern  and  50  carloads 
from  the  central  and  northern  portions  of  California.1 

The  total  acreage  of  tomatoes  in  California  grown  for  the  can- 
neries during  1914  was  approximately  10,000  acres  and  the  estimated 
acreage  for  1915,  6,000  acres.     Several  hundred  acres  are  yearly  de- 

*  Revision  of  Bulletin  No.  239  of  this  Station. 

i  California  Fruit  News,  December  26,  1914,  p.  53. 


voted  to  growing  this  vegetable  for  eastern  and  local  fresh  markets. 
The  culture  of  this  crop  is  widely  distributed  throughout  California 
and  there  is  probably  not  a  county  in  which  it  is  not  grown  during 
some  season  of  the  year.  The  principal  counties  producing  tomatoes 
in  California,  however,  are  Los  Angeles,  Orange,  Alameda,  Santa 
Clara  and  Sonoma.  There  is  also  a  considerable  acreage  throughout 
certain  portions  of  the  San  Joaquin  and  the  Sacramento  valleys.  The 
production  of  tomatoes  for  eastern  fall  and  winter  shipments  is  largely 
carried  on  in  southern  California.  Aside  from  the  large  acreages 
above  referred  to,  this  crop  is  very  important  to  the  miscellaneous 
vegetable  grower  so  that  it  holds  a  conspicuous  place  in  many  of  the 
market  and  home  gardens  throughout  the  state. 

YIELD 
The  average  yield  per  acre  of  tomatoes  grown  for  the  canneries 
varies  from  8  to  10  tons.  Under  favorable  conditions  and  with  proper 
care,  yields  of  from  15  to  20  tons  and  occasionally  of  25  tons  per  acre 
are  realized.  The  average  yield  obtained  when  producing  tomatoes 
for  the  fresh  markets  varies  from  10  to  12  tons  per  acre,  while  occas- 
ionally 20  to  25  tons  per  acre  are  secured. 

COST  OF  PEODUCTION  AND  PRICES  RECEIVED 
The  cost  of  producing  tomatoes  for  the  canneries  varies  from 
$25.00  to  $45.00  per  acre,  the  average  being  $32.00.  The  cost  of  rais- 
ing tomatoes  for  the  fresh  markets  varies  from  $35.00  to  $50.00  per 
acre,  the  average  being  $40.00.  The  prices  paid  by  the  canneries  vary 
from  $6.00  to  $8.00  per  ton,  while  the  prices  paid  on  the  fresh  markets 
vary  from  $10.00  to  $40.00  per  ton,  the  average  being  about  $20.00. 
The  growers  often  realize  more  than  the  figures  given  above,  especially 
when  the  crop  is  matured  during  the  early  spring  or  late  fall. 

CULTURE  REQUIREMENTS 
Soil. — Tomatoes  are  grown  on  a  large  variety  of  soils  varying  from 
adobe  to  sand;  the  most  favorable  being  largely  dependent  upon  the 
season  of  growth  and  the  uses  to  which  the  crop  is  to  be  put.  This 
crop  is  better  adapted  to  soils  of  ordinary  quality  than  many  other 
vegetables,  for  if  the  soil  contains  an  over  supply  of  nitrogen,  or 
moisture,  the  growth  of  the  plants  will  go  to  vine  at  the  expense  of 
the  crop.  If,  on  the  other  hand,  it  is  deficient  in  plant  food  and 
moisture,  the  growth  of  the  plants  will  be  stunted  with  a  consequent 
lessening  of  the  yield.  The  most  desirable  soil  for  the  early  spring 
and  late  fall  crop  is  a  sandy  loam,  rich  in  plant  food  and  underlaid 


from  3  to  5  feet  by  a  heavier  stratum.  For  the  mid-summer  and  can- 
ning crop  a  medium  heavy  loam  fairly  rich  in  plant  food  and  holding 
moisture  well  will  be  found  the  most  satisfactory.  As  the  tomato  is  a 
deep-feeding  crop,  there  should  be  from  3  to  5  feet  of  good  soil. 

Climate. — The  tomato  is  easily  injured  by  cold  but  will  endure 
heat  well  provided  the  soil  moisture  is  optimum.  Temperatures  vary- 
ing from  80  to  90  degrees  during  the  day  and  60  or  70  degrees  during 
the  night  are  well  adapted  to  the  needs  of  this  crop.  It  is  possible  in 
certain  sections  of  the  state  to  grow  tomatoes  unprotected  in  the  field 
from  February  to  December,  inclusive,  but  the  weather  conditions 
throughout  the  greater  part  of  California  prohibit  their  cultivation 
before  March  and  after  November. 

Moisture. — The  moisture  requirements  of  the  tomato  are  moderate 
but  in  order  that  maximum  crops  may  be  produced,  there  should  be  an 
adequate  amount  of  moisture  throughout  the  season.  If  growing  dur- 
ing the  hot  weather  the  plants  should  have  a  larger  supply  than  under 
cooler  conditions.  A  considerable  quantity  of  tomatoes  is  grown  in 
California  without  irrigation,  but  in  producing  this  crop  during  the 
hot  summer  months  and  especially  in  the  interior  valleys  of  the  state, 
irrigation  is  generally  practiced.  The  plants  are  easily  injured  by 
excessive  amounts  of  moisture  and  hence  require  good  soil  drainagej 
especially  during  the  rainy  season. 


PREPARATION  OF  THE  SOIL 

In  the  preparation  of  the  field,  deep  fall-plowing  should  be  prac- 
ticed where  possible.  If  the  soil  is  of  a  heavy  nature,  it  may  be  left  in 
the  plowed  condition  until  spring,  but  on  the  lighter  soils  the  fields  are 
generally  worked  down  immediately  to  a  good  condition  of  tilth. 
Unless  the  soil  is  very  deficient  in  plant  food  it  is  not  customary  to 
apply  manure  or  commercial  fertilizers  previous  to  planting.  When 
manure  is  applied,  it  should  be  spread  on  the  soil  in  the  fall  at  the 
rate  of  from  5  to  15  tons  per  acre,  plowed  under  immediately  and 
allowed  to  rot  thoroughly  before  the  plants  are  set. 

A  few  weeks  before  planting,  the  soil  may  either  be  replowed,  or 
disced,  to  a  depth  of  from  8  to  10  inches ;  the  former  method  being 
used  when  the  weed  growth  is  luxuriant.  After  working  in  the 
spring,  the  earth  should  be  brought  into  as  fine  a  condition  of  tilth 
as  possible  so  that  at  the  time  of  planting  all  weed  growth  is  checked 
and  a  fine  mulch  is  formed.  Just  previous  to  planting  the  field  should 
be  marked  off  to  show  where  the  plants  are  to  be  located. 


GROWING  THE  PLANTS  IN  THE  SEED  BEDS 

There  are  three  methods  used  in  California  for  growing  the  young 
plants.  Those  who  produce  tomatoes  for  early  spring  markets  raise 
their  plants  in  hot-beds,  but  for  the  mid-summer  and  fall  crops,  cold- 
frames  or  open  beds  may  be  used.  When  it  is  especially  desirable  to 
produce  early  plants,  small  berry  baskets  may  be  placed  in  the  hot- 
bed filled  with  earth  and  the  seed  planted  in  them.  After  the  danger 
from  frost  has  passed  and  the  plants  are  from  six  to  ten  inches  tall, 
the  baskets  containing  the  plants  may  be  taken  from  the  beds  and  set 
in  the  field,  basket  and  all,  as  the  baskets  will  soon  decay  they  will  not 
interfere  with  the  root  growth  of  the  plants.  Where  this  method  is 
used  several  seeds  should  be  sown  in  every  basket  and  the  plants  later 
thinned  to  one. 

The  customary  method  for  raising  the  plants  in  the  seed  beds  is 
by  sowing  the  seed  in  drills  from  three  to  six  inches  apart  or  by  broad- 
casting. The  former  method  is  preferable  for  the  grower  who  has  had 
a  limited  experience  or  for  purposes  of  producing  rapidly  growing 
plants.  Soil  which  is  used  for  this  purpose  should  be  light  in  char- 
acter and  worked  to  a  very  fine  condition  of  tilth  before  seeding.  It 
is  desirable  also  to  spade  under  a  heavy  coating  of  stable  manure  long 
enough  in  advance  of  seeding  to  insure  thorough  rotting.  It  will  aid 
in  germinating  the  seed  if  burlap  or  muslin  be  placed  on  the  surface 
of  the  ground  until  the  plants  have  appeared,  at  which  time  it  should 
be  removed.  The  seed  should  be  covered  with  from  one  quarter  to 
one  half  inch  of  soil  and  it  will  be  found  desirable  to  use  sand  for  this 
purpose,  especially  if  the  soil  in  the  bed  is  of  a  heavy  nature.  The 
location  of  the  beds  should  be  on  a  well-drained  spot,  preferably  on  the 
south  side  of  a  fence  or  building.  Water  should  be  piped  to  the  beds 
so  that  they  may  be  sprinkled  with  the  least  effort. 

Care  of  Plants  in  the  Seed  Beds. — It  is  very  important  that  the 
beds  be  sprinkled  often  enough  to  keep  the  surface  moist,  watering 
frequently  rather  than  putting  on  larger  amounts  at  longer  intervals. 
Many  growers  sprinkle  their  seed  beds  lightly  once  or  twice  a  day  until 
the  plants  have  appeared  at  the  surface.  Where  the  surface  covering 
has  been  used  the  water  may  be  applied  through  it.  Care  should  be 
taken,  however,  not  to  have  the  soil  too  wet,  for  the  young  plants  are 
very  susceptible  to  an  over  supply  of  moisture.  Where  very  early 
plants  are  desired,  the  growers  sometimes  heat  the  water  before  apply- 
ing it.  After  the  seedlings  have  appeared  at  the  surface,  the  watering 
should  be  done  very  carefully  and  consistently.  The  frequency  of 
watering  should  be  governed  entirely  by  the  condition  of  the  plants 


and  there  is  more  danger  from  over-irrigation  than  from  putting  on 
an  insufficient  amount.  During  cold  cloudy  weather,  the  beds  should 
not  be  watered  unless  absolutely  necessary  and  the  sprinkling  should 
be  done  preferably  on  clear  mornings,  allowing  the  surface  of  the  soil 
and  the  tops  of  the  plants  to  dry  before  night. 

After  the  seedlings  are  from  two  to  four  inches  in  height  they 
should  be  thinned,  leaving  a  space  of  from  two  to  five  inches  between 
plants.  At  this  time  the  beds  should  be  carefully  weeded  and  if  the 
seed  has  been  sown  in  drills,  the  soil  between  the  rows  should  be  thor- 
oughly stirred.  A  week  or  so  before  the  plants  are  to  be  taken  from 
the  beds,  watering  should  be  stopped  and  if  they  have  been  grown 
under  some  protection,  this  should  gradually  be  removed  in  order  that 
they  may  become  "hardened  off,"  for  if  the  plants  are  removed  when 
they  are  growing  rapidly,  it  will  be  found  very  difficult  to  get  them 
established  in  the  field  without  seriously  checking  their  growth.  A 
few  hours  before  removing  the  plants,  the  beds  should  be  thoroughly 
wet  to  aid  in  preserving  the  fibrous  roots  that  are  so  important  in 
quickly  establishing  the  plants  in  the  field.  If  the  plants  have  grown 
too  large,  the  tops  should  be  cut  off  to  about  six  or  eight  inches  from 
the  ground  before  being  transplanted. 

There  are  several  methods  for  removing  the  plants  from  the  beds, 
but  whichever  is  practiced,  care  must  be  taken  to  remove  them  in  such 
a  way  that  their  root  systems  are  disturbed  as  little  as  possible.  The 
experienced  grower  may  be  able  to  remove  them  from  the  bed  properly 
by  pulling  them  up  by  the  tops  but  it  is  always  best  to  use  some  imple- 
ment, such  as  a  shovel  or  trowel,  cutting  off  the  roots  about  four  inches 
below  the  surface  of  the  ground  and  taking  as  much  earth  up  with 
the  plants  as  possible.  The  plants  may  either  be  placed  in  pans  or  in 
baskets,  or  rolled  in  sacks  and  carried  to  the  field,  care  being  taken  not 
to  expose  their  roots  to  the  air  any  longer  than  is  necessary. 

PLANTING   IN   THE  FIELD 

During  the  early  spring,  the  soil  generally  contains  sufficient 
moisture  to  start  the  plants  without  the  aid  of  irrigation,  but  during 
the  late  spring  and  summer  it  is  customary  to  irrigate  at  the  time  of 
setting.  Where  irrigation  is  necessary  furrows  from  six  to  eight 
inches  deep  are  plowed,  on  the  edges  of  which  the  plants  are  set. 
Water  is  run  in  these  furrows  at  the  time  of  planting.  Where  it  is 
impossible  to  irrigate  by  the  above  named  method,  the  furrows  are  un- 
necessary but  water  should  be  hauled  to  the  young  plants  and  the 
earth  around  every  one  thoroughly  wet. 


The  holes  in  which  the  plants  are  set  should  be  large  enough  to 
accommodate  all  the  roots  and  after  planting  the  earth  should  be 
packed  firmly  around  every  plant.  These  holes  may  be  made  by  the 
use  of  a  spade,  trowel,  dibble  or  scandigie ;  the  latter  implement  being 
especially  adapted  for  this  kind  of  work  and  used  principally  by  the 
Italians.  The  depth  to  which  the  plants  are  set  is  dependent  upon 
their  size  and  the  character  and  condition  of  the  soil,  but  they  should 
be  planted  two  to  three  inches  deeper  than  they  were  when  growing 
in  the  seed  bed.  Deeper  planting  during  the  summer  than  in  the  early 
spring  is  the  rule.  After  the  field  has  been  set  for  a  week  or  ten  days, 
it  should  be  examined  carefully  and  plants  set  in  the  spaces  in  which 
the  original  plants  failed  to  start.  The  distance  between  the  plants 
varies  with  the  variety,  season,  character  of  the  soil  and  the  water 
supply. 

When  grown  for  the  early  spring  market,  especially  if  a  small  vine 
variety  is  used,  the  plants  may  be  set  four  to  six  feet  apart,  in  rows 
six  feet  apart.  The  usual  distance  between  the  plants  when  growing 
the  main  and  canning  crop  varies  from  six  by  six  to  seven  by  seven 
feet. 

CULTIVATION 

The  exact  number  of  cultivations  which  the  field  will  require  de- 
pends upon  the  type  of  soil,  moisture  supply,  season  and  the  weed 
growth.  As  soon  as  the  plants  have  revived  from  the  transplanting, 
the  field  should  be  hoed  and  cultivated,  care  being  used  not  to  come 
too  close  to  the  plants.  Thorough  and  persistent  cultivation  while 
the  plants  are  small  will  lessen  the  cost  of  production  for  it  is  ex- 
pensive and  difficult  to  cultivate  the  field  after  the  plants  have  at- 
tained their  growth.  Under  ordinary  conditions,  the  field  should  be 
cultivated  from  four  to  six  times  and  hand-hoed  two  or  three  times 
during  the  season.  A  thorough  cultivation  should  follow  every 
irrigation. 

IRRIGATION 

In  growing  tomatoes  during  the  early  spring  or  in  certain  coast 
sections  at  other  seasons,  irrigation  is  often  unnecessary  as  the  natural 
amount  of  soil  moisture  is  sufficient  to  produce  satisfactory  crops  pro- 
vided the  cultivation  is  thorough.  In  the  interior  valleys  and  in  the 
southern  part  of  the  state,  the  growers  are  generally  obliged  to  irri- 
gate their  fields  when  growing  tomatoes  during  the  hot  dry  months. 
Where  this  is  practiced,  the  water  should  be  applied  often  enough  so 


that  the  plants  are  never  allowed  to  suffer  from  drouth  at  any  time 
during  their  growth. 

There  are  two  periods  when  it  is  undesirable  to  apply  water: 
(1)  Over-irrigation  during  the  time  of  blossoming  will  cause  the 
blooms  to  drop,  which  materially  decreases  the  yield  ;  (2)  if  the  water 
is  used  too  late  during  the  growth  of  the  plants,  the  fruit  will  be 
watery,  making  it  unfit  for  shipment  and  reducing  the  quality.  As 
a  rule,  water  is  applied  soon  after  transplanting  to  the  field,  and  a 
second  irrigation  is  given  after  the  fruit  has  set.  Occasionally  one 
or  two  more  irrigations  are  necessary  from  then  until  the  crop  has 
commenced  to  mature,  but  it  is  better  to  irrigate  seldom  and  cultivate 
often,  rather  than  to  put  on  the  water  too  frequently.  At  every  irri- 
gation a  sufficient  amount  of  water  should  be  applied,  so  that  the  soil 
is  thoroughly  wet  to  a  depth  of  from  three  to  five  feet,  for  if  small 
amounts  are  applied,  more  frequent  irrigations  are  necessary  and  the 
plants  will  have  a  tendency  to  produce  a  shallow  root  system  which  is 
undesirable.  The  most  common  method  for  applying  water  is  by  run- 
ning it  in  furrows  four  to  six  inches  deep  between  the  rows  and  from 
one  to  two  feet  from  the  plants.  The  water  should  be  run  down  these 
furrows  as  slowly  as  possible,  in  order  that  it  may  penetrate  to  a 
considerable  depth  and  the  furrows  should  be  cultivated  as  soon  after 
irrigation  as  the  condition  of  the  soil  will  permit. 

HAEVESTING 

The  method  by  which  the  crop  is  harvested  depends  largely  upon 
its  disposal.  For  the  early  spring  crop,  which  is  generally  sold  in  the 
local  markets,  the  tomatoes  should  be  nearly  matured  before  being 
removed  from  the  vines,  and  carefully  packed  in  lug  boxes  or 
baskets. 

When  packed  for  the  canneries,  the  fruit  is  placed  in  lug  boxes 
holding  approximately  thirty-five  pounds,  and  then  hauled  to  the  cars 
or  canneries.  Tomatoes  which  are  used  for  this  purpose  should  be 
matured  at  the  time  of  harvesting.  While  this  market  can  use  fruit 
which  would  be  too  coarse  for  the  fresh  market,  the  grower  should 
examine  the  tomatoes  very  carefully  and  all  wormy,  over-ripe,  or 
green  tomatoes  should  be  discarded. 

When  packing  for  long-distance  shipments,  the  grower  should  be 
extremely  careful  that  only  fruit  of  the  highest  quality  is  used.  After 
having  been  picked  from  the  vines,  the  crop  is  generally  hauled  in  lug 
boxes  on  spring  wagons  or  in  wagons  in  which  straw  has  been  placed, 
to  the  packing  house,  where  the  tomatoes  are  very  carefully  wrapped 


8 

in  tissue  paper  and  re-packed  in  baskets  holding  five  pounds  each; 
four  of  which  constitute  a  crate.  These  are  loaded  immediately  upon 
cars  and  shipped  to  their  destination.  Fruit  which  is  thus  disposed  of 
is  generally  picked  a  few  days  before  it  has  matured. 

It  is  very  important  that  the  vines  be  disturbed  as  little  as  pos- 
sible during  harvesting.  It  is  a  good  plan  to  pull  off  all  wormy  or 
undesirable  tomatoes,  as  the  field  is  gone  over,  and  to  burn  these  in 
piles  or  haul  them  off  the  field.  Great  care  should  be  used  in  handling 
the  tomatoes,  for  every  bruise  may  start  a  rot  in  a  few  days,  and 
under  no  circumstances  should  the  stems  be  allowed  to  remain  on 
the  fruit. 


VARIETIES 

During  the  past  few  years  growers  have  realized  more  than  ever 
before  that  there  is  a  large  variation  in  the  yield  from  individual 
plants  of  the  same  variety.  It  has,  therefore,  become  customary  for 
the  grower  to  go  into  his  field,  picking  out  the  plants  which  come 
nearest  to  his  ideal  and  saving  the  crop  for  his  future  seed  supply. 
It  is  important  in  order  that  this  may  be  efficient,  that  several  seasons 
be  spent  in  this  selection,  choosing  at  every  season  the  vines  which 
are  best  adapted  for  one's  use.  In  selecting  seed,  the  grower  should 
consider  the  whole  crop  on  the  vine  and  not  the  individual  tomato; 
for  the  plants  which  are  raised  in  the  future  will  resemble  more  closely 
the  entire  crop  which  has  been  produced  on  the  vine  rather  than  the 
individual  tomato  from  which  the  seed  was  taken.  If  this  selection 
is  carried  on  carefully,  the  results  in  a  few  years  should  be  superior 
to  those  when  ordinary  seed  is  used.  The  varieties  which  are  the  most 
popular  in  California  are  the  Sparks'  Earliana,  Stone,  Trophy  and 
San  Filippo. 

Sparks'  Earliana. — This  is  especially  popular  and  highly  recom- 
mended for  the  early  spring  markets  for  which  use  it  is  chiefly  grown. 
The  vine  growth  is  not  very  vigorous  and  the  fruit  sunburns.  It  is 
not  a  good  shipper,  but  is  well  colored,  of  medium  size  and  round. 

Trophy. — Grown  chiefly  in  the  San  Francisco  Bay  region  for  can- 
neries. It  is  a  heavy  producer  although  the  fruit  will  not  keep  well 
and  is  rough. 

Stone. — A  general  favorite  on  the  market.  Used  throughout  Cali- 
fornia for  the  local  fresh  markets,  eastern  shipping,  and  canneries. 
The  fruit  is  highly  colored,  a  good  shipper,  and  excellent  in  quality. 
The  vine  growth  is  luxuriant  and  heavy  bearing,  and  the  fruit  does 
not  sunburn  easily. 


San  Filippo. — Grown  chiefly  throughout  the  San  Francisco  Bay 
sections  and  especially  in  the  vicinity  of  San  Jose  for  the  canneries. 
Is  well  colored,  firm,  and  a  desirable  variety. 


DISEASES  OF  THE  TOMATO 

Damping  Off  in  the  Seed  Bed. — This  disease  is  mainly  trouble- 
some to  the  young  plants  and  commonly  is  the  cause  of  large  losses. 
Damping  Off  is  due  to  several  different  fungi,  the  most  common  being 
Rhizoctonia,  Fusarium,  Botrytis  and  Sclerotinia.  It  is  mainly  trouble- 
some during  cold  damp  weather,  especially  from  the  time  the  plants 
have  come  through  the  surface  until  they  grow  to  a  height  of  from 
four  to  six  inches.  This  disease  is  characterized  at  first  by  the  death 
of  a  few  plants  scattered  through  the  seed  bed  and  under  favorable 
conditions  these  isolated  diseased  plants  will  infect  the  surrounding 
soil,  causing  circular  diseased  areas  throughout  the  bed.  An  infected 
plant  falls  over  as  if  it  had  been  cut  off,  quickly  wilts  and  dies. 

In  the  control  of  this  disease  care  should  be  taken  not  to  use  too 
much  water  on  the  surface  of  the  soil  and  the  tops  of  the  plants  should 
be  kept  as  dry  as  possible.  After  the  disease  has  appeared,  the  water- 
ing should  be  stopped  until  it  is  necessary  to  irrigate  the  plants  in 
order  to  keep  them  alive.  The  bed  should  be  well  ventilated  and  the 
plants  should  never  be  closer  than  two  inches  apart.  After  the  disease 
has  appeared,  a  small  trench  may  be  dug  around  the  infected  area, 
which  will  check  its  spread  to  the  still  healthy  plants.  Spray  with 
Bordeaux  Mixture,  using: 

Blue  Stone  3  pounds 

Lump  Lime    4  pounds 

Water    50  gallons 

If  the  disease  is  still  uncontrollable,  the  bed  should  be  discarded  and 
a  new  one  started.  Soil  which  has  become  infected  should  not  be  used 
the  following  season  for  growing  the  young  plants,  as  the  fungi  con- 
cerned are  capable  of  living  in  the  soil  a  considerable  time. 

Failure  to  Set  Fruit. — It  is  very  commonly  found  in  California 
that  while  the  vines  set  a  heavy  crop  of  blossoms,  many  of  the  latter 
fall  at  the  time  the  tomatoes  should  be  forming.  This  may  be  caused 
by  the  climatic  conditions,  such  as  rain,  cold,  or  heavy  fog,  extremely 
dry  weather  or,  in  fact,  any  condition  which  would  prevent  proper 
scattering  of  the  pollen  and  fertilization  of  the  blossoms.  Irrigation 
at  the  time  the  blooms  are  setting  is  often  responsible  for  this  trouble 


10 

and  if  the  growth  of  the  plant  is  going  to  vine  instead  of  fruit  due  to 
over-richness  of  the  soil  in  nitrogen,  it  appears  to  aid  this  condition. 
Occasionally  insects  eat  into  the  blossoms  which  injures  the  latter  and 
makes  them  useless.  For  the  control  of  this  disease  the  growers  should 
find  out,  if  possible,  which  of  the  foregoing  conditions  is  responsible 
for  the  failure  of  the  fruit  to  set  and  remedy  it  as  best  they  can. 

Late  or  Winter  Blight. — When  growing  tomatoes  during  the  rainy 
season  an  entire  crop  is  sometimes  lost  from  this  disease,  but  no  trouble 
is  occasioned  during  the  dry  months,  except  in  a  few  sections  along 
the  coast  where  there  are  heavy  fogs.  The  disease  attacks  all  portions 
of  the  plant  above  ground  where  it  causes  black  lesions  to  appear.  It 
is  caused  by  the  fungus  Phytophthora  infestans.  This  disease  may 
be  controlled  by  spraying,  as  soon  as  it  appears,  with  Bordeaux  Mix- 
ture made  up  as  follows : 

Blue  Stone   5  pounds 

Lump  Lime  6  pounds 

Water    50  gallons 

Blossom  End  Rot. — This  disease  is  very  commonly  found  in  Cali- 
fornia and  is  characterized  by  the  appearance  of  circular  pale  yel- 
lowish areas  at  the  blossom  end.  No  parasite  has  been  found  which 
is  directly  responsible  for  the  appearance  of  this  disease,  though  it 
may  be  due  to  splitting  of  the  skin  which  allows  fungoid  and  bacterial 
organisms  which  later  cause  the  decay  to  gain  entrance.  Under  Cali- 
fornia conditions  it  is  found  chiefly  in  sections  in  which  the  amount 
of  soil  moisture  is  inadequate  or  where  water  has  been  applied  at  too 
irregular  intervals.  It  more  commonly  appears  on  plants  grown  on 
soils  of  a  light  nature. 

This  disease  may  be  controlled  by  keeping  an  optimum  amount  of 
moisture  in  the  soil  during  the  entire  growth  of  the  plants.  Where 
irrigation  is  practiced,  the  water  should  be  put  on  at  regular  intervals 
so  that  the  plants  may  not  suffer  for  moisture  at  any  time  during  their 
growth. 

Root  Knot. — Occasionally  when  tomatoes  are  growing  in  sandy 
soil,  the  vines  will  suddenly  commence  to  turn  yellow,  growth  stops 
and  they  slowly  die.  Upon  examination  of  the  tops  of  the  plants,  no 
unnatural  spots  on  the  vines  or  fruit  may  be  seen,  but  upon  pulling 
up  these  vines,  the  root  system  will  be  found  to  be  largely,  if  not 
entirely,  rotted  away  and  the  few  remaining  roots  distorted  and  de- 
cayed. This  condition  is  caused  by  the  nematode  worm  Heterodera 
radicioola.      These  minute  worms  are  whitish  in  color,  pear  shaped, 


11 

about  the  size  of- a  pin  point,  and  can  be  seen  by  cutting  into  the  galls 
or  swellings.  The  plant  is  affected  in  four  ways:  1.  The  water  car- 
rying ducts  are  deranged,  making  it  impossible  for  food  material  to 
pass  into  the  tissues  of  the  plant.  2.  The  cracks  make  very  good  places 
for  bacterial  and  fungoid  organisms  to  gain  entrance  and  rot  the 
roots.  3.  The  feeding  of  the  worms  upon  the  tissues  of  the  plant. 
4.  General  weakening  of  the  plant,  making  it  more  susceptible  to  at- 
tacks from  other  organisms. 

These  worms  are  capable  of  living  in  the  soil  for  an  indefinite 
number  of  years,  provided  suitable  plants  are  present  for  them  to 
live  upon.  Although  the  plants  may  be  healthy  when  set  in  the  field, 
these  parasites,  if  present,  will  gain  entrance  into  the  roots  of  the 
growing  plants.  Occasionally  soil  in  which  seedlings  are  grown  is 
infected  and  where  this  condition  prevails,  a  large  percentage  of  the 
plants  will  be  diseased  while  growing  in  the  beds. 

The  control  of  the  Nematode  worm  is  somewhat  problematic  and  in 
some  cases  it  has  been  found  exceedingly  difficult  to  eradicate  this 
pest.  The  following  measures  of  control  are  recommended :  1.  Plant- 
ing a  crop,  such  as  rape  or  mustard,  which  is  very  susceptible  to 
Nematode  infection,  plowing  it  up  and  burning  it  after  the  females 
are  in  the  roots,  but  before  the  eggs  have  had  a  chance  to  hatch. 

2.  Growing  crops  in  the  affected  fields  for  a  number  of  years  upon 
which  these  worms  cannot  feed,  such  as  corn,  sorghums,  barley,  etc. 

3.  Thoroughly  drying  the  soil  so  that  the  worms  may  be  starved. 
Where  this  method  is  practiced,  no  crop  should  be  planted.  4.  Soil 
which  is  to  be  used  for  seed  beds  should  be  known  to  be  free  from 
Nematode  infection.  5.  As  soon  as  a  plant  has  become  infected,  it 
should  be  pulled  up  and  the  space  which  it  formerly  occupied  allowed 
to  remain  vacant. 

Leaf  Spot. — This  disease  is  found  principally  during  the  early 
spring  while  the  plants  are  in  the  seed  beds,  and  at  which  time  there 
is  considerable  moisture  in  the  atmosphere.  Throughout  the  more 
humid  sections  of  the  United  States,  this  disease  is  more  or  less 
troublesome  in  the  field,  but  owing  chiefly  to  climatic  conditions  in 
California  it  has  never  been  found  serious  after  the  plants  have  been 
transplanted.  It  is  caused  by  the  fungus  Septoria  lycopersici.  "Where 
this  trouble  appears  in  the  seed  bed,  the  plants  should  be  sprayed 
with  the  following  mixture  : 

Blue  Stone  3  pounds 

Lump  Lime    4  pounds 

Water'  50  gallons 


12 

If  the  disease  is  troublesome  in  the  field,  spray  with  Bordeaux  Mix- 
ture made  up  as  follows: 

Blue  Stone   5  pounds 

Lump  Lime  6  pounds 

Water    50  gallons 

Generally   one   or   two   sprayings   will   be   sufficient   to   control   this 
trouble. 

Sunburn. — This  condition  is  often  troublesome  during  the  hot 
months,  especially  through  the  interior  sections  of  California.  Sun- 
burn is  characterized  by  a  discoloration  of  the  tomatoes  making  them 
unfit  for  the  market.  Where  this  occurs  the  planting  should  be  done 
as  early  in  the  season  as  possible  and  a  variety  should  be  used  which 
has  a  luxuriant  vine  growth,  such  as  the  Stone,  in  order  that  the  fruit 
may  be  protected. 

Summer  Blight. — This  disease  is  often  very  troublesome  to  the 
growers  and  during  certain  seasons  is  the  cause  of  enormous  losses. 
It  is  characterized  b}^  the  dying  of  individual  plants  throughout  the 
field,  usually  after  the  first  hot  weather  in  the  spring.  A  field  which 
is  affected  by  this  disease  will  appear  at  a  distance  as  if  the  stand  of 
plants  were  poor  but  upon  closer  examination  these  apparently  vacant 
spots  will  be  found  to  contain  dead  plants. 

Upon  examining  a  plant  which  has  recently  become  affected,  the 
veins  of  the  leaves  on  the  under  side  will  be  found  to  be  purple  in 
color.  The  leaves  curl  upward,  turn  yellow  and  the  growth  of  the 
plant  stops.  Upon  cutting  off  the  top,  the  plant  will  be  found  to 
bleed  very  little,  showing  a  scarcity  of  sap.  During  the  past  few  years 
many  experiments  have  been  carried  on  in  order  to  determine  the 
cause  and  remedy  for  this  trouble,  but  so  far  as  known,  the  direct 
cause  has  never  been  found  and  only  a  partial  remedy  is  known. 
Plants  set  in  the  field  after  June  do  not  become  nearly  so  seriously 
infected  as  when  planted  early  in  the  season. 

In  a  similar  disease  which  occurs  in  the  state  of  Washington,  it 
has  been  found  that  when  the  seed  is  planted  directly  in  the  field, 
without  transplanting,  the  trouble  is  largely  avoided.  Summer  Blight 
may  appear  in  fields  which  are  growing  tomatoes  for  the  first  time, 
and  even  continuous  culture  of  the  crop  for  a  number  of  years  has 
apparently  no  effect  upon  its  decrease  or  increase.  Among  many 
varieties  tested  for  their  resistance  to  the  blight,  there  is  no  striking 
difference. 


